Manufacture of fire-resisting materials.



No. 668,562. Patented Feb. l9, l90l.

A. IMSCHENETZKY.

MANUFACTURE OF FIRE BESISTING MATERIALS.

(Application filed Dec. 7, 1899.)

(No Model.)

wj w/ww ihmmw m: uoams wars! on. PHQYO-LITHII, WA5NINHYON, n, c.

UNTTED STATES PATENT EEicE.

MANUFACTURE OF FIRE-RESISTING MATERIALS.

SPECIFICATION forming part of Letters Patent No. 668,562, dated February 19, 1901.

Application filed December 7, 1899. Serial No. 739,501. (No Specimens.)

T0 00% whom it WI/OLZ/ concern:

Be it known that I, ALEXANDER IMSCHEN- ETZKY, a subject of the Emperor of Russia, residing at St. Petersburg, Russia, have invented certain new and useful Improvements in and Relating to the Manufacture of Fire- Resisting Materials, of which the following is a specification.

My invention relates to the manufacture of asbestos cardboard and like materials and is chiefly designed to produce a stronger and more homogeneous material than has been possible heretofore.

In the manufacture of asbestos cardboard and other similar bodies the mixed mass is introduced into a cardboard or paper making machine and rolled up onto a collecting-roller in successive layers.

In the accompanying drawing I have shown one form of apparatus suitable for carrying out my inyention and in which the figure is a sectional elevation.

Now I have discovered that such substances are greatly improved if colloidal silica is deposited gradatt'm during the building up of the compound sheet, such deposition being produced by the reaction described and claimed in the specification of former Letters Patent granted to me and dated June 25,

1899, No. 629,567, and August 22, 1899, No.

631,719. To effect this, I cause a roller 2, of wood or other material, covered with a woven or knitted tube or stocking 3, of woolen or other material, to engage with the advancing face of the drum or cylinder 1 on which such cardboard is being deposited. The roller 2 revolves in frictional contact with a roller 4,

which is partly immersed in a trough 5, supplied through the pipe 6 or by other suitable means with a silicate-of-s'odium solution of any desired strength. I prefer to use a solution of 30 Baume; but I do not bind myself to that or any other special degree of concentration. The roller 2 is pivotally mounted in arms 7, turning about the same axis as the roller 4, a hand-lever 8, pivoted at 9 and suitably connected to the arms 7, being provided for bringing the roller 2 into and out of contact with the drum or cylinder 1. The cardboard material or mass 10 is supplied to the drum or cylinder 1 by means of a traveling Web or-felt 11 or in any other suitable manner. The drum or cylinder 1, with the cardboardthereon, rolling in contact with the stocking-covered roller 2 causes the roller 4 to revolve in the trough 5, and by contact the sheet of cardboard as it winds up is thorougly moistened or wetted with the silicate solution. When the collecting drum or cylinder 1 has revolved through a suitable angle-for example, one hundred and eighty degreesthe cardboard thereon is caused to engage with a second stocking-covered roller 12, in frictional contact with a similar roller 13, which is similarly in contact with a roller 14, partly immersed in a trough 15. The rollers 12 13 14 are mounted in arms 16, pivotally mounted so as to turn about the axis 18, the said arms being connected to a handlever 17, pivoted at 18, to enable them to be moved so as to bring the roller 12 into and out of engagement with the drum or cylinder 1. The trough 15 is supplied, through a pipe 19 or by other suitable means, with a solution of sodium hydrogen carbonate, (sodium bicarbonate,) which I prefer to be of a strength of 8 Baum. I do not, however, confine myself to the above-mentioned or any other special concentration for the bicarbonate solution which I prefer to use, nor do I confine myself to the use of sodium bicarbonate, as I can employ any other salt or substance which will conveniently decompose sodium silicate with deposition of colloidal silica. The result of this treatment is, assuming bicarbonate of soda to be employed, that each component Web or layer of the compound sheet is first coated with sodium-silicate and then with sodium-hydrogen-carbonate solutions, such coatings being successive and in the order named and such double coatings being interposed between each web or layer of the compound sheet. The colloidal silica formed by the reaction of the solutions from the troughs 5 and 15 on each other assists in uniting the several layers together to form a strong and homogeneous sheet. When a sufficient number of layers have been deposited on the drum 1 to produce a sheet of the desired thickness,the said sheet is Washed, pressed, and dried, after which it is removed from the drum 1 by dividing it along a line preferably parallel to the axis of the said drum, or, if desired, it can be removed from the drum before it is Washed, pressed, and dried.

\Vhat I claim is 1. A process for the manufacture of asbestos cardboard and like material, consisting in winding the cardboard. material in the form of a strip onto itself so as to form an endless band of any desired perimeter, and as each layer is Wound, applying to the said material, first, a solution of a silicate, and secondly, a solution capable of decomposing such silicate with the formation of colloidal silica, and after a sufficient number of layers have been deposited, drying the product, substantially as, and for the purposes, hereinbefore described.

2. A process for the manufacture of asbestos cardboard and like material, consisting in winding the cardboard material in the form of a strip onto itself so as to form an endless band of any desired perimeter, and as each layer is wound, applying to the said material, first, a solution of sodium silicate, and secondly, a solution of sodium-hydrogen carbonof about 30 Baum and afterward a solution of sodium-hydrogen carbonate of a strength about 8 Baum, and after a sufficient number of layers have'been deposited, drying the product, substantially as, and for the purposes, hereinbefore described.

In Witness whereof I have hereunto set my hand in presence of two- Witnesses.

ALEXANDER IMSCHENETZKY.

Witnesses:

M. BREITFUSS, E. LoURBE. 

